Fuel flow control device



lll'fl'lllh INVENTOR.

HTTOENEQ y 1951 R. w. JOHNSON FUEL FLOW CONTROL DEVICE WWW li l V Filed Sept. 8, 1947 Patented May 15, 1951 UNITED STATES PATENT OFFICE FUEL FLOW CONTROL DEVICE Roy W. Johnson, Milwaukee, Wis.

Application September 8, 1947, Serial No. 772,726

8 Claims. 1

This invention relates to improvements in devices of the constant level type for controlling the flow of fuel oil from a reservoir to a burner of the gravity feed type and in which the same means is used to vary the liquid level and to control the flow of fuel for both high and pilot flame operation of the burner.

In a constant level flow control device, such as shown, for example, in U. S. Letters Patent 2,293,903, issued to me on August 25, 1942, a casing defines a main chamber and an auxiliary chamber, and oil is admitted to the main chamher by an inlet valve which is spring urged toward open position and is closed by a float proportionately as the oil lever within the main chamber varies. The oil may flow from the main or supply chamber to a burner under the control of a metering valve which is adjustable to vary the flow as required to maintain a desired high flame at the burner. When the metering valve is closed so that the burner is not operating at the high flame, it is necessary to keep a pilot flame ignited to provide for immediate ignition of oil upon reopening of the metering valve and thus prevent flooding of the burner with oil. In the device shown in the above identified patent, separate means is provided to control the flow of fuel to the burner for high and pilot flame operation thereof.

The pilot flow control means should be accurately variable to provide for the relatively small variations required to compensate exactly for viscosity (temperature) changes of the oil or changes in the composition of the oil itself. A passage of relatively small cross-sectional area may be used to control the flow of oil, provided that the length of the passage is variable and that the parts defining the passage are so constructed as to be readily removable for cleaning and replaceable without the necessity for critical readjustments in the device. If such passage (herein designated capillary passage), is to be used also for controlling the flow of oil for high flame burner operation, it is necessary that both the cross-sectional area and the length of the capillary passage be variable within a wide range to permit adjustment for passing both the relatively large quantity of oil required for high flame operation of the burner and the relatively small quantity of oil required for pilot flame operation of the burner, with the accuracy required to maintain the pilot flame under varying conditions. If the quantity of oil which may be passed through the capillary passage, is insuflicient under some high fire conditions, it

is necessary to provide means for raising the oil level without otherwise changing the operatio of the device.

It is accordingly one object of the present invention to provide a device of the constant level type for controlling the flow of fuel oil to a burner of the gravity feed type, with single means controlling the oil flow for both high and pilot flame operation of the burner.

Another object of the invention is to provide a fuel flow control device of the constant level type with a capillary passage which is adjustable both as to cross-sectional area and length for controlling the flow of fuel therethrough within the wide range of limits required for both high and pilot flame burner operation, and with the accuracy necessary for proper pilot flame maintenance.

Another object of the invention is to provide an adjustable leverage by which the level of the oil within the main chamber in the device, may be varied without varying the setting of but varying the range of flow through the means controlling the flow of oil from the chamber to a burner.

Another object of the invention is to provide a flow control device of the constant level type including a leverage for controlling the flow of oil into the device and in which one fulcrum point in the leverage may be shifted from exteriorly of the device to vary the oil level therein without changing the functioning of the leverage.

Objects and advantages other than those above set forth will be apparent from the following description when read in connection with the accompanying drawing in which:

Fig. 1 is a top plan view of the device with the cover removed therefrom;

' Fig. 2 is a cross-sectional View taken on the plane of broken line H ll of Fig. 1;

Fig. 3 is a cross-sectional view taken on the plane of line IIIIII of Fig. 2;

Fig. 4 is an enlarged fragment of Fig. 3;

Fig. 5 is a cross-sectional view taken on the plane of line IV--IV of Fig. 4;

Fig. 6 is a fragment of Fig. 2 showing the inlet valve and its relation to the main float; and

Fig. '7 is a side elevation of one element of the device.

Generally, the present device comprises a casing divided substantially into a main and an auxiliary chamber by a partial partition. The main chamber is connected with an oil inlet passage through an inlet valve which is urged toward open position by a spring and is moved toward closed position by the act of a float in the chamber as the oil level varies therein. If the inlet valve fails to close when the oil level rises above a given point, a float in the auxiliary chamber actuates means for completely and forcibly closing the inlet valve. Oil flows from the main chamber through a single means by which the flow of oil is controlled for both high flame and pilot flame operation of the burner. Such means includes a plug fixed in the casing main chamber and substantially inclosed bya sleeve to define therewith a capillary passage which is variable both in cross-sectional area and in length, upon movement of the sleeve axially of the plug. Means is provided for vary: ing the oil level upon the Qdcurrencc of high flame fuel requirements which cannot be met by adjustment of the capillary passage.

Referring particularly to the drawings, l geneia ly esiehet s a s ng ha in i Partial P rtit ll; therein for dividing the casing into a main chamber 12 and an auxiliary chamber l3. The crest of the partition II is slightly higher than the highest level to which the oil is to rise in chamber I; and retains the oil in such chamber except when the oil level rises above the highest desired value whereupon the oil may flow over the partition into the auxilary chamber I3. An inlet passage i4 is formed in the casing for connection with a reservoir of liquid fuel (not hewm- Th in e pas age 1 s c n d w h he ain c amb r y e hes es th u h e ee whi is interierl th ead d to ec e t valve ea in er edy 19 form d h n a a p g and ran v rs pf ls ik t er h e for o necting the inlet passage [4 with the main chamber 12. The valve casing I9 has an internal sh u de rmed t rei below he i heture 0f the passages therein, to provide a seat for the pointed end of a needle valve 21} which is urged tow d. eh e itie b a s ne 2i empre e betwe va ve easin I9 nd flang d sleeve ca rie on the a e stem- A nut, 23 rry washer is threaded on the upper end of sleeve 2.2 hil a cu ped flange member 22' is, s a n he lev end e he ee e sp n 24 is som pr sed. between Washer 25. and cuppe memb r; to c sh on he amm ble of th a y strike 38.-

7 Means is provided or var in th d gree ei ening of he inl t val 21 r sp nsive techanges in level in the oil in chamber l2 and for; va yin s c e e su means in ude e e ese o wh ch one u rum i a u ab i em. e ter rly of the casi wh reby t e e v l t maintained in he main c amb ma b ch n e wi hout. a e tin t pe a of h in e al control means. A bracket 25 is fixed in the cas-i n jus beneath a o er herefo nd supp t a pivot pin 28 or a l v r ha g a si g arm 30 and a d0u e arm 3 a an a e t h single arm somewhat as in a bell-crank lever. The lever is so designed that the lever arm 30 ay t nd su stantial y paralle i the sever and be engaged by a screw 32 threaded into the cover. The double lever arm 3l extends to adjacent, the nut 23 to support a pivot 33 for anarm 3 f x d. o e flee 3. a ene e d en havin the other end rockably engageable with the nut 3 a d e an 5 fo essin d wnwar en he e e v l e s h fle t 35 i r sed y the ris n oil level. Hence, the degree ofopeningof the inlet valve is contrglled dependent on variatien in h ei level with e ees nema n 7 determined by theminimum and maximum extension of screw 32 through the cover.

Means is also provided for completely and forcibly seating the needle valve 20 if the oil level rises above the maximum value desired therefor in the chamber l2. Such means includes a striker plate 38 mounted on the edges of ears extending therefrom, in (the. sides of bracket 26.

The striker plate extends over the end of the nee. dle valve and is urged to swing about its bearing ears, in a counter-clockwise direction, by a tension spring 39 acting between an end of the striker plate and the bracket 26. So longas the oil level does not rise above the predetermined value, the. striker plate is latched in a given position against the action of the spring 39, by eneasement of an end of the plate by the jaw-like end of a lever 40 pivoted on the pin 21 and pivotally connected with a float 4| in auxiliary chamber l3. The action of the above means in completely and forcibly seating the valve 28 under given circumstances is clearly described in my above identified patent and is accordingly not repeated herein.

A plug generally designated is fixed in the main chamber l2 to be. partiall inclosed by a sleeve generally designated 46, the sleeve and pl ceet n in form ng a capillary assage which is variable both in cross-section area and in length. The plug has a frusto-conical porn .1 and a cylindrical portion 48 fitting n movable relation into a frusto-conical portion 52 and a cylindrical portion 53 respectively of the sleeve. A groove 54 is for-med about the p u at the juncture of the frustorconical and cylindrical surfaces thereof and the groove is connected by an aperture 55 with a passage 55 axially through the plug. The plug also has a c-ylin dri cal portion 51 pressed into a socket formed in the wall of the casing 10 to aline and join the plug passage 56 with a passage 59 in the wall of the casing. Passage. 59, is connected with an outlet passage 60 from the casing, Which compares with the outlet passage for the metering valve in the pat t abov d scr bed a i dapted t be connected to a fuel burner. In the present in-. vention, however, the metering valve. is omitted and the upper end of the passage 50 is closed by a plug 6|.

The upper end of sleeve {8 is closed for seating a spring .65 between the end of plug 45 and the closed end of the sleeve whereby the sleeve is urged to move axially of the plug in the direction; for increasing the spacing between the plug coni cal portion 41 and'the. well conical portion 52;. The lifting action of the spring: on the sleeve may be adjusted by adjusting a screw 66 threaded into the casing cover and bearing on the end of the sleeve for limiting the expansion of-the spring. The plug passage 56 is connected with the space above the, oil level, in the casing by an aperture. 6] in the cylindrical wall 53 of the sleeve and above the highest oil level,

When the parts of the, present device are in the positions shown onlysufficient oil flows through th capillary passaga the plug passage and the outlet passage to maintain a pilot flame at the burnerfor a given viscosity of a particular oil. If the temperature or con uposition of the oil changes in such manner to reduce. the flow thereof, the sleeve 46 may be shifted axially on;- th us t neree e he ress-s e ie a ea and de re se the l iigt ei the p lary Passage, e

thereby compensate for oil changes during pilot flame operation. When'a high flames operation of the burner is desired, the quantity of oil necessary for such operation may also'be obtained within given limits by movement of the sleeve. However, if the sleeve movement is not sufficient to produce the desired high flame under particular conditions, then screw 32 is threadedfarther into the cover to press down on the end of the lever arm 35! which swings the lever counterclockwise about its pivot 21 to raise the end of lever arm 3|. Such movement of the lever arm lifts the pin 33 which is the fulcrum for float 35 and raises the oil level in chamber l2 at which the float 35 will commence to cause closing of valve 20. a

Whenever it becomes necessary to clean the capillary passage, it is necessary only to remove the sleeve from the casing whereupon the corresponding conical surfaces of the sleeve and plug, the groove of the plug and the axial passage in the plug may be readily cleaned to maintain their original flow characteristics. It is usually unnecessary to clean the cylindrical surfaces of the plug and sleeve for the reason that axial movement of the sleeve over the plug maintains such surfaces sufficiently clean to prevent any difiiculty in moving the sleeve.

It will be seen that the present invention provides a structure in which a capillary passage controls the flow of oil both for the high and pilot flame operations of a liquid fuel burner, without at any time interrupting the flow of oil to the burner. The inlet and discharge ends of the capillary passage are both below the minimum oil level in the supply chamber so that the volume of oil is variable merely by varying the axial position of the sleeve about the plug. The sleeve may readily be shifted to compensate for changes in oil characteristics or to obtain any desired flow for high fire operation and the oil level in the casing main chamber can be readily raised if shifting of the sleeve does not provide a sufliciently wide range of volume variation. The sleeve is readily replaceable Without disturbance in other adjustments of the device so that the device may be kept in its best operating condition by a relatively unskilled person.

Although but one embodiment of the present invention has been illustrated and described, it will be apparent to those skilled in the art that various changes and modifications may be made therein without departing from the spirit of the invention or from the scope of the appended claims.

I claim:

1. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage, a plug mounted in the casing and having a passage therethrough connected with the chamber and the outlet passage, a sleeve mounted about the plug for axial movement relative thereto, the plug and the sleeve having conical portions co-acting in defining a capillary passage for maintaining a continuous flow of fuel to the burner, and means for axially adjusting the sleeve about the plug to vary the effective cross-sectional area of and to vary the flow of fuel through the capillary passage.

2. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage, a plug mounted in the casing and having a passage therethrough connected with the chamber and the outlet passage, a sleeve mounted about the plug for axial movement relative thereto, the plug and the sleeve having conical portions co-acting in defining a capillary passage connected with the plug passage by an aperture through the plug for maintaining a continuous flowof fuel to the burner, and means for axially adjusting the sleeve about the plug to vary the effective cross-sectional area of and to vary the flow of fuel through the capillary passage.

3. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage therein, a plug mounted in the casing and having a passage connecting with the chamber and the outlet passage, the plug having a cylindrical portion and a conical portion, a sleeve mounted about the plug for axial movement relative thereto and having a cylindrical portion receiving the cylindrical plug portion and a conical portion co-acting with the conical plug portion in defining a capillary passage for maintaining a continuous flow of fuel to the burner, and means for axially adjusting the sleeve about the plug to vary the effective cross-sectional area of and to vary the flow of fuel through the capillary passage.

4. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage, a plug mounted in the casing and having a passage therethrough connected with the chamber and the outlet passage, a sleeve mounted about the plug for axial movement relative thereto, the plug and the sleeve having conical portions co-acting in defining a capillary passage for maintaining a continuous flow of fuel to the burner, and means for axially adjusting the sleeve about the plug to vary the effective cross-sectional area of and to vary the fiow of fuel through the capillary passage, the sleeve and plug havin a common axis for maintaining uniform spacing between the conical sleeve and plug portions upon axial r movement of the sleeve about the plug.

5. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage, a plug mounted in the casing and having a passage therethrough connected with the chamber and the outlet passage, a sleeve mounted about the plug for axial movement relative thereto, the plug and the sleeve having conical portions co-acting in definin a capillary passage for maintainin a continuous flow of fuel to the burner, and means for axially adjusting the sleeve about the plug to vary the effective cross-sectional area of and to vary the flow of fuel through the capillary passage, the plug having a cylindrical portion extending into the casing outlet passage for retaining the plug in alinement with and in sealing engagement with the outlet passage.

6. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage, a plug mounted in the casin and having a passage therethrough connected with the chamber and the outlet passage, a sleeve mounted about the plug for axial movement relative thereto, the plug and the sleeve having conical portions co-acting in defining a capillary passage for maintaining a continuous flow of fuel to the burner, the plug having a passage therethrough and having a roove thereabout adjacent, the conical plug portion and having an aperture connecting the passage, through the plug and the groove, the capillary passagetogether with .the groove and aperture in the plug and the passage therethrough providing a path for the flow of :fuel therethrough.

7. A device controlling the flow of liquid fuel to a burner of the gravity feed type and comprising a casing having a fuel supply chamber with an outlet passage, a plug mounted in the casing and-having a passage therethrough connected with the chamber and the outlet passage, a sleeve mounted about the plug for axial movement relative thereto, the plug and the sleeve having conical portions co-acting in defining a capillary passage for maintaining a continuous flow f fuel to the burner, a spring acting between the plug and the sleeve for urging the sleeve axially of the plug in the direction for increasing the cross-sectional area and decreasing the length of the capillary passage, and means operable from exteriorly of the easing for adjusting the action of the spring.

8. A device controlling the fiow of liquid fuel to a burner "of the gravity feed type and'comprising a covered casing having a fuel supply chamber with an outlet passage, a plug mounted 8 inthe casing and having a passage there-'- through connected with. the chamber and the outlet passage, a sleeve mounted about the plug for axial movement :relative thereto, the plug and the sleeve having conical portions co-actln in defining a capillary passage for maintaining a continuous flow of fuel to the burner, a spring actin between the plug and the sleeve for urging the sleeve axially of the plug in the direction for increasing the cross-sectional area and decreasing the length of the capillary passage, and a screw threaded into the casing cover for adjusting the action of the spring.

' ROY W. JOHNSON.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 804,999 Hart Sept. 9, 1884 833,672 Huther Oct. '16, 1906 2,068,138 Johnson Jan. 19, 1937 2,172,647 Widman Sept. 12, 1939 2,234,088 Russel Mar. 4, 19.41 2,244,161 Johnson June 3, 1941 2,309,770 Johnson Feb. 2, 1943 

